This research pertains to the exploration of the effects upon the mechanical strain response of Magnetostrictive/Piezoelectric composites when immersed in intense electromagnetic fields generated from overhead lines, and how they can be transferred to an optical fiber to modulate light and measure the external field. This research proposal is focused mainly on the geometrical shape effects of the composite and how their effects can be used to obtain more sensitivity, less demagnetization field effect, and more transduction efficiency and frequency response. Initially, a theoretical analysis of different magnetization/polarization and magnetostriction/electrostriction models for ferromagnetic/ferroelectric materials will be performed with the aim to determine the physical variables associated to current models and their effects in the proposed application. This analysis will be supported with numerical simulations that allow to evaluate the interaction of the external fields and the distribution of the internal field inside the materials. It is known that geometrical effects on the composite have a significant role in the mechanical interaction not only because it affects the field distribution but also because it determines the method of coupling to the optical fiber and the way how light signal will be modulated. Therefore, a theoretical assessment of this latter issue and the identification of the main key facts in the strain-stress transference will be also addressed. In the interaction between the external magnetic field and the magnetostrictive material, Eddy’s currents are expected due to temporal changes of the magnetic field and the intrinsic conductivity of the material, this latter can be controlled by the epoxy resin ratio in the composite. This factor will help to improve the response of the magnetic dipoles to faster changes in the external magnetic field. Finally, and based on the research results, it will be proposed a suitable fiber optic sensor arrangement based on Magnetostrictive/Piezoelectric composites such as they could measure electromagnetic fields in a high voltage single-phase overhead line.